Harpoon Therapeutics Reports Clinical Progress Across All Four TriTAC® Pipeline Development Programs
HPN424 has shown confirmed partial response in treatment of metastatic castration-resistant prostate cancer in highest fixed dose cohort (160 ng/kg) of continuing Phase 1/2a dose escalation trial
Three of seven patients in highest fixed dose HPN424 cohort have shown PSA reduction
Dose escalation trials advancing for HPN536 and HPN217 with initial data readouts and initiation of expansion cohorts expected in 2021
Management to host clinical update webcast/call today, December 8, 2020, at 8 a.m. ET
”We are pleased to provide a trial update to our shareholders today, as well as outline our expectations for 2021. We have made significant progress in all of our clinical development programs in 2020,” stated
“We are pleased to report the activity we are seeing with HPN424 in late-stage prostate cancer patients in our highest fixed dose cohort tested to date,” said
Clinical Program Updates
(All data as of
Dose escalation continues in Phase 1/2a trial for HPN424 in the treatment of mCRPC. As of the
At the highest fixed dose tested to date, 160ng/kg, one patient out of 7 has experienced a confirmed partial response with tumor lesion reduction of 43%, and 3 of 7 patients have had serum PSA declines from baseline, including one patient with a PSA reduction greater than 50%.
HPN424 was generally well tolerated and cytokine-related adverse events have been manageable. Reported Grade 3 or higher adverse events have included cytokine release syndrome (CRS) (10%), ALT increase (11%) and AST increase (11%). CRS events and transaminitis have been transient and have not resulted in treatment discontinuation. Dose-limiting toxicities (DLTs) have been observed and have not limited escalation. A maximum tolerated dose (MTD) has not been identified. Presentation of Phase 1 data and initiation of an expansion cohort is planned for the first half of 2021. Interim data from this expansion cohort is anticipated by the end of 2021.
HPN536 (mesothelin TriTAC) Phase 1/2a clinical trial continues escalation. Dosing has occurred across 9 fixed-dose cohorts of 6 to 280ng/kg and 1 step dose cohort up to 600ng/kg. Tumor types treated include late-stage ovarian and pancreatic cancers and peritoneal mesothelioma. Enrolled patients had a median of four prior systemic therapies, and 66% of patients had progressive disease as best response to their most recent prior therapy. Pharmacokinetic analysis shows median half-life of more than 70 hours. Among the relapsed/refractory ovarian cancer patients with at least one post-baseline scan, 8 of 12 (67%) patients showed stability of target lesions.
HPN536 appears to be well tolerated. One CRS grade 3 occurred in the absence of dexamethasone premedication treatment. The CRS resolved, and the patient continued on study with dexamethasone premedication. As of
Dose escalation for HPN217 (BCMA TriTAC) Phase 1/2 clinical trial progressing rapidly. Relapsed/refractory multiple myeloma patients have been treated across 6 single-patient fixed dose cohorts of 5 to 810µg, reflecting a more than 100-fold increase in dose in 8 months. HPN217 has been well-tolerated, and no DLTs have been observed as of the
First patient dosing anticipated for HPN328 (DLL3 TriTAC) by the end of 2020. The first site is open and recruiting for the dose escalation portion of this Phase 1/2 clinical trial. In the first cohort, the patients will receive a flat dose of 15µg of HPN328 administered once weekly by intravenous infusion. Eligible patients include small cell lung cancer patients who have relapsed after platinum chemotherapy and patients with other tumors associated with DLL3 expression. Presentation of initial data is planned for the second half of 2021.
Webcast and Conference Call
Harpoon’s management will host a webcast and conference call at
About Harpoon Therapeutics
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Chief Financial Officer
Source: Harpoon Therapeutics